1. Field of the Invention
The invention relates to a device for welding together thermoplastic hoses with two clamping units which can be rotated and displaced in parts relative to each other and have two clamping units having clamping jaws and with through-passages between the clamping jaws in which the hoses can be inserted continuously parallel to each other and squeezed transversely to each other, and with a heatable blade for cutting through the hoses and melting their cut edges between the clamping units.
Such devices are used for example in biotechnology and in medicine, when it is necessary to produce sterile hose connections between a cell culture and a nutrient medium or between a dialysis patient and a bag for the rinse solution. By squeezing the hose, fluid contained in it is prevented from coming out during the welding process and possibly contaminating the surroundings. At the end of the welding process, all the hose ends are closed. This is also called total containment under moist welding conditions.
2. Description of the Prior Art
A prior-art apparatus is known from EP 0 778 123 in which after the hoses are cut through, one of the clamping units is turned by 180° and then the hose sections that come into alignment with each other through this turning are welded to each other. In the through-passages of the two clamping units, the hoses in this apparatus are stacked directly on top of each other and are squeezed therein directly transversely on each other. It is not apparent how a hose which after turning and being welded on both sides is joined with a container, can again come out of the clamping units. Owing to the configuration of the turning support, the known apparatus is quite voluminous.
In the apparatus from EP 0 507 321, provision is also made for two clamping units that can be turned relative to each other. Into them, the hoses are inserted in two through-passages placed at a distance from each other, and then squeezed perpendicular to their common positional plane. The means for supporting the clamping units is not described.